Real World Events
- March: The first Halo figures by McFarlane Toys were released.
- April 3: The Darkness trailer was released.
- April 15: The Legendary Map Pack for Halo 3 was released.
- July 14: The Five Long Years Cinematic trailer for Halo Wars was shown at E3 2008.
- July 15: An apology message about the postponing of the announcement of Bungie's new project, which was to be shown at E3, was posted at Bungie.net. The project would later be revealed as Halo 3: ODST.
- September 25: The Keep It Clean trailer was released.
- October 4: The trailer Field Trip To Harvest was released.
- October 8: Halo 3: ODST, then called Halo 3: Recon, was officially announced at Tokyo Game Show 2008.
Community content is available under CC-BY-SA unless otherwise noted.